JP2023502391A - Digital ping lockout for multi-coil wireless charging devices - Google Patents

Abstract

A system, method and apparatus for wireless charging are disclosed. A charging device includes a plurality of charging cells provided on a charging surface, a charging circuit, and a controller. The controller is configured to detect objects proximate to the surface of the charging device by passive ping. The controller is also configured to ping the detected object with an active ping and to determine if a ping response is received from the object in response to one or more active pings from the charging device. there is Further, the controller may detect an active ping of the detected object if no ping response is received at the charging device after a count of consecutively emitted active pings from the at least one coil exceeds a preset number. configured to stop. As a result, digital ping lockout occurs when the passive ping detects an object that does not respond to the active ping. [Selection drawing] Fig. 14

Description

TECHNICAL FIELD This invention relates generally to wireless charging of batteries, including batteries of mobile computing devices, and more particularly to preventing repeated pings emitted by a wireless charging device when an unresponsive device is placed on the wireless charging device. about doing

PRIORITY CLAIM This application is based on U.S. patent application Ser. This application claims priority to and benefit from application Ser. The entire contents of are hereby incorporated by reference for all applicable purposes, as if fully set forth below.

Wireless charging systems have been developed to allow certain types of devices to charge their internal batteries without using a physical charging connection. Devices capable of wireless charging include mobile processing devices and/or mobile communication devices. Standards such as the Qi standard defined by the Wireless Power Consortium allow devices manufactured by a first supplier to be wirelessly charged using chargers manufactured by a second supplier. Wireless charging standards are optimized for relatively simple configurations of devices and tend to provide basic charging functionality.

Conventional wireless charging systems typically use a "ping" to determine if a receiving device is on or in proximity to a transmission coil of a base station for wireless charging. A transmission coil has an inductance (L) and a resonant capacitor having a capacitance (C) is coupled to the transmission coil to obtain a resonant LC circuit. Ping is generated by powering a resonant LC circuit. Power is applied for a period of time while the transmitter listens for a response from the receiving device. Additionally, in multi-coil wireless charging devices, ping can be used to determine the optimal combination of coils to use to charge the battery of the receiving device.

Improved wireless charging capabilities are necessary to support ever-increasing complexity of mobile devices and changing form factors. For example, a faster, lower-speed device that allows a charging device to detect and locate a rechargeable device on its surface, as well as detect removal or repositioning of a rechargeable device during wireless charging operation. A need exists for power sensing techniques.

FIG. 1 illustrates an example charging cell that may be provided on a charging surface provided by a wireless charging device in accordance with certain aspects disclosed herein. FIG. 2 illustrates an example arrangement of charging cells provided on a single layer of charging surface segments provided by a wireless charging device in accordance with certain aspects disclosed herein. FIG. 3 illustrates an example arrangement of charge cells where multiple layers of charge cells are stacked within segments of a charging surface provided by a wireless charging device in accordance with certain aspects disclosed herein. there is FIG. 4 illustrates an arrangement of power transfer areas provided by a charging surface of a charging device employing multiple layers of charging cells configured in accordance with certain aspects disclosed herein. FIG. 5 illustrates a wireless transmitter that may be provided at a charger base station in accordance with certain aspects disclosed herein. FIG. 6 illustrates a first example response to a passive ping, in accordance with certain aspects disclosed herein. FIG. 7 illustrates a second example response to a passive ping, in accordance with certain aspects disclosed herein. FIG. 8 illustrates examples of observed differences in responses to passive pings, in accordance with certain aspects disclosed herein. FIG. 9 illustrates a first topology supporting matrix multiplexed switching for use in wireless chargers adapted according to certain aspects disclosed herein. FIG. 10 illustrates a second topology supporting DC drive in a wireless charger adapted according to certain aspects disclosed herein. FIG. 11 illustrates a multi-coil wireless charging system configured to reliably detect removal of a receiving device in accordance with certain aspects of the present disclosure. FIG. 12 is a flowchart illustrating a method including passive ping implemented in a wireless charging device adapted according to certain aspects disclosed herein. FIG. 13 is a flowchart illustrating power transfer management procedures that may be employed by wireless charging devices implemented in accordance with certain aspects disclosed herein. FIG. 14 illustrates an example situation of a receiving device placed in close proximity to a wireless charging device that may result in the use of digital ping lockout. FIG. 15 is a flowchart illustrating a digital ping lockout procedure that may be employed in accordance with aspects disclosed herein. FIG. 16 illustrates an example apparatus employing processing circuitry that may be adapted in accordance with certain aspects disclosed herein. FIG. 17 illustrates a method for operating a charging device according to certain aspects of the disclosure.

DETAILED DESCRIPTION The detailed description set forth below in conjunction with the accompanying drawings is intended to describe various configurations and is intended to represent only one configuration in which the concepts described herein may be implemented. not a thing The detailed description includes specific details to provide a thorough understanding of various concepts. However, it will be clear to one skilled in the art that these concepts may be practiced without specific details. At times, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

Several aspects of wireless charging systems are now presented with reference to various apparatus and methods. These devices and methods are described in the following detailed description and shown in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). shown. These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system.

For example, an element, any portion of an element, or any combination of elements may be implemented with a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic, discrete hardware circuits, and throughout this disclosure. Other suitable hardware configured to perform the various functions described are included. One or more processors of the processing system may execute software. Software includes instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, whether referred to as software, firmware, middleware, microcode, hardware description languages, etc. , software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, and the like. The software may reside in a processor readable storage medium. Processor-readable storage media, also referred to herein as computer-readable media, include, for example, magnetic storage devices (eg, hard disks, floppy disks, magnetic strips), optical disks (eg, compact discs (CDs), digital versatile discs (DVDs)). , smart cards, flash memory devices (e.g. cards, sticks, key drives), near field communication (NFC) tokens, random access memory (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, carrier waves, transmission lines, or any other medium suitable for storing or transmitting software. A computer-readable medium may be resident in the processing system, external to the processing system, or distributed among multiple entities including the processing system. A computer-readable medium may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure, depending on the particular application and overall design constraints imposed on the overall system. .

Overview Certain aspects of this disclosure relate to systems, apparatus and methods applicable to wireless charging devices and techniques. The charging cell may consist of one or more inductive coils to provide a charging surface for the charging device, which allows the charging device to wirelessly charge one or more rechargeable devices. to The location of the device being charged can be detected by sensing techniques that relate the location of the device to changes in physical properties about known locations on the charging surface. Position sensing may be performed using capacitive, resistive, inductive, touch, pressure, load, strain and/or another suitable type of sensing.

In one aspect of the present disclosure, an apparatus includes a battery charging power supply, a plurality of charging cells arranged in a matrix, and each switch configured to couple a row of coils in the matrix to a first terminal of the battery charging power supply. and a second plurality of switches, each switch configured to couple a column of coils in the matrix to a second terminal of the battery charging power supply. Each charge cell in the plurality of charge cells can include one or more coils surrounding a power transfer region. The multiple charge cells can be positioned adjacent to the charging surface of the charging device without overlapping the power transfer areas of the charge cells within the multiple charge cells.

In some implementations, the device is also referred to as a charging surface. Power can be wirelessly transmitted to a receiving device located anywhere on the surface of the apparatus. The devices can have any defined size and/or shape and can be placed regardless of the individual placement position where they are made chargeable. Multiple devices can be charged simultaneously on a single charging surface. The device can track movement of one or more devices across the charging surface.

Charge Cells According to certain aspects disclosed herein, charge cells in a charging device can be used to provide a charge surface, where the charge cells are deployed adjacent to the charge surface. In one example, charging cells are deployed in one or more layers of the charging surface according to a honeycomb package configuration. A charging cell can be implemented with one or more coils each capable of inducing a magnetic field along an axis substantially orthogonal to the charging surface adjacent to the coil. As used herein, a charge cell is an element having one or more coils, each coil being additive to the electromagnetic fields produced by the other coils in the charge cell and along a common axis. It can refer to an element configured to generate an electromagnetic field directed at or in close proximity.

In some aspects, a charge cell includes coils that are stacked along a common axis and/or overlap to contribute to an induced magnetic field that is substantially orthogonal to the charge surface. In some aspects, the charge cell includes a coil disposed within a defined portion of the charge surface that contributes to an induced magnetic field within substantially orthogonal portions of the charge surface associated with the charge cell. In some aspects, the charge cell may be configurable by providing an excitation current to a coil included in the dynamically defined charge cell. For example, the charging device may include multiple stacks of coils arranged across the charging surface, the charging device detecting the location of the device to be charged, selecting some combination of stacks of coils, and , can provide charging cells adjacent to the device to be charged. In some examples, a charge cell may include or be characterized as a single coil. However, it should be understood that a charge cell may include multiple stacked coils and/or multiple adjacent coils or stacks of coils. Coils are sometimes referred to herein as charging coils, wireless charging coils, transmitter coils, transmission coils, power transmission coils, power transmitter coils, and the like.

FIG. 1 illustrates an example charging cell 100 that may be deployed and/or configured to provide a charging surface for a charging device. As described herein, a charging surface can include an array of charging cells 100 provided on one or more substrates 106 . Circuitry including one or more integrated circuits (ICs) and/or discrete electronic components may be provided on one or more substrates 106 . The circuit can include drivers and switches used to control the current that is supplied to coils used to transmit power to the receiving device. The circuitry may be configured as processing circuitry including one or more processors and/or one or more controllers that may be configured to perform the specific functions disclosed herein. In some implementations, some or all of the processing circuitry may be provided external to the charging device. In some implementations, a power source can be coupled to the charging device.

The charging cell 100 can be provided in close proximity to the outer surface area of the charging device, on which one or more devices can be placed for charging. A charging device may include multiple instances of charging cells 100 . In one example, the charging cell 100 surrounds one or more coils 102 constructed with conductors, wires or circuit board traces capable of receiving sufficient current to generate an electromagnetic field in the power transfer region 104; It has a substantially hexagonal shape. In various aspects, some coils 102 can have shapes that are substantially polygonal, including the hexagonal charging cell 100 shown in FIG. In other embodiments, coils 102 having other shapes can be provided. The shape of the coil 102 may be determined, at least in part, by manufacturing technology capabilities or limitations and/or to optimize the layout of the charge cells on a substrate 106, such as a printed circuit board. Each coil 102 may be implemented using a spiral configuration of wire, printed circuit board traces and/or other connectors. Each charge cell 100 may span two or more layers separated by insulators or substrates 106 such that the coils 102 of different layers are centered about a common axis 108 .

FIG. 2 illustrates an example arrangement 200 of charging cells 202 provided on a single layer of segments of a charging surface of a charging device that may be adapted in accordance with certain aspects disclosed herein. The charge cells 202 are arranged according to a honeycomb package configuration. In this example, the charge cells 202 are arranged end-to-end without overlapping. This arrangement can be provided without through-holes or wire interconnections. Other arrangements are possible, including an arrangement in which portions of the charge cells 202 overlap. For example, the wires of two or more coils may be interleaved to some extent.

FIG. 3 illustrates an example arrangement of charge cells from two perspectives 300, 310 when multiple layers are stacked in segments of a charge surface that can be adapted according to certain aspects disclosed herein. ing. Layers of charge cells 302, 304, 306, 308 are provided in segments of the charge surface. The charge cells within each layer of charge cells 302, 304, 306, 308 are arranged according to a honeycomb package configuration. In one example, the charge cell layers 302, 304, 306, 308 may be formed on a printed circuit board having four or more layers. The placement of charge cells 100 can be selected to completely cover the designated charge area adjacent to the segments shown.

FIG. 4 illustrates an arrangement of power transfer areas provided on a charging surface 400 employing multiple layers of charge cells configured in accordance with certain aspects disclosed herein. The illustrated charge surface is composed of four layers 402, 404, 406, 408 of charge cells, which may correspond to the charge cell layers 302, 304, 306, 308 of FIG. In FIG. 4, each power transfer area provided by a charge cell in the first layer of charge cells 402 is labeled "L1" and each power transfer area provided by a charge cell in the second layer of charge cells 404 is denoted as "L1". The transmission area is labeled "L2" and each power transfer area provided by a charge cell in the third layer of charge cells 406 is labeled "L3" and the charge cells in the fourth layer of charge cells 408 are labeled "L3". Each power transfer region provided by is labeled "L4".

Wireless Transmitter FIG. 5 shows a wireless transmitter 500 that can be provided at the charger base station. Controller 502 may receive the feedback signal filtered or otherwise processed by conditioning circuit 508 . A controller can control the operation of a driver circuit 504 that provides alternating current to a resonant circuit 506 that includes a capacitor 512 and an inductor 514 . The resonant circuit 506 is also referred to herein as a tank circuit, an LC tank circuit, or an LC tank, and the voltage 516 measured at the LC node 510 of the resonant circuit 506 is also referred to as the tank voltage.

Wireless transmitter 500 can be used by charging devices to determine whether a compatible device has been placed on the charging surface. For example, a charging device can determine when a compatible device is placed on a charging surface by transmitting an intermittent test signal (active ping or digital ping) via wireless transmitter 500, causing resonance. Circuitry 506 can detect or receive the encoded signal when a suitable device responds to the test signal or alters the characteristics of the test signal. The charging device may be configured to activate one or more coils in at least one charging cell after receiving a response signal defined by a standard, convention, manufacturer or application. In some examples, a compatible device may respond to a ping by communicating the received signal strength so that the charging device can find the best charging cell to use to charge the compatible device.

Passive ping techniques use the voltage and/or current measured or observed at LC node 510 to identify the presence of a receive coil in proximity to the charging pad of a device adapted according to certain aspects disclosed herein. can be used. In many conventional wireless charger transmitters, circuitry is provided to measure the voltage at the LC node 510 or to measure the current in the LC network. These voltages and currents can be monitored for power regulation purposes or to support communication between devices. In the example shown in FIG. 5, the voltage at LC node 510 is monitored, but it is contemplated that the current is additionally or alternatively monitored to support passive pings in which short pulses are provided to resonant circuit 506. It is The response of resonant circuit 506 to a passive ping (initial voltage V ₀ ) can be indicated by the voltage (V _LC ) at LC node 510 as follows.

According to certain aspects disclosed herein, coils within one or more charging cells can be selectively activated to provide optimal electromagnetic fields for charging compatible devices. In some examples, coils may be assigned to charge cells such that some charge cells overlap other charge cells. In the latter example, the optimal charging configuration can be selected at the charging cell level. In another example, charging cells can be defined based on the placement of the device to be charged on the surface of the charging device. In these other examples, the combination of coils activated for each charging event may be different. In some implementations, a charging device can include a driver circuit that can select one or more cells and/or one or more preset charging cells to activate during a charging event.

FIG. 6 shows a first example where the response 600 to a passive ping decays according to Eq. It can be seen that after the excitation pulse at time t=0, the voltage and/or current oscillate at the resonant frequency defined by Eq. 1 with a damping rate defined by Eq. The first cycle of oscillation begins at voltage level V ₀ and V _LC continues to decay to zero as controlled by the Q factor and ω. The example shown in FIG. 6 shows a typical open or no load response when no object is present or near the charging pad. A Q value of 20 is assumed in FIG.

FIG. 7 shows a second example where the response 700 to a passive ping decays according to Eq. It can be seen that after the excitation pulse at time=0, the voltage and/or current oscillate at the resonant frequency defined by Eq. 1 with a damping rate defined by Eq. The first cycle of oscillation begins at voltage level V ₀ and V _LC continues to decay to zero as controlled by the Q factor and ω. The example shown in FIG. 7 shows a load response where an object is at or near the charging pad to load the coil. In FIG. 6, the Q value can have a value of seven. V _LC oscillates at a higher frequency in voltage response 700 than in voltage response 600 .

表１では、Ｑ値を次のように計算することができる。

ここで、Ｎは、励起から振幅が０．５Ｖ_０を下回るまでのサイクル数である。 FIG. 8 shows a series of examples in which differences in responses 800, 820, 840 are observed. A passive ping is initiated when the driver circuit 504 excites the resonant circuit 506 with a pulse shorter than 2.5 μs. Different types of radio receivers and foreign objects placed on the transmitter result in different observable responses in the transmitter's LC node 510 voltage or resonant circuit 506 current. These differences may indicate variations in the Q factor of the frequency of resonant circuit 506 of oscillation at V ₀ . Table 1 shows specific examples of objects placed on the charging pad in relation to the open state.

In Table 1, the Q value can be calculated as follows.

where N is the number of cycles from excitation until the amplitude drops below _0.5V0 .

Selectively Activated Coils According to certain aspects disclosed herein, the transmission coils within one or more charging cells can be selectively activated to provide optimal electromagnetic fields for charging compatible devices. can be activated. In some examples, the transmission coils may be assigned to charge cells such that some charge cells overlap other charge cells. In the latter example, the optimal charging configuration can be selected at the charging cell level. In another example, charging cells can be defined based on the placement of devices to be charged on the charging surface. In these other examples, the combination of coils activated for each charging event may be different. In some implementations, a charging device can include a driver circuit that can select one or more cells and/or one or more preset charging cells to activate during a charging event.

FIG. 9 illustrates a first topology 900 supporting matrix multiplexed switching for use in wireless chargers adapted according to certain aspects disclosed herein. A wireless charger can select one or more charging cells 100 to charge a receiving device. Charge cells 100 that are not in use can be disconnected from current flow. A relatively large number of charge cells 100 can be used in the honeycomb package configuration shown in FIG. 2 requiring a corresponding number of switches. According to certain aspects disclosed herein, charge cells 100 are logically arranged into a matrix 908 having a plurality of cells connected to two or more switches that allow a particular cell to be powered. can be placed. In the illustrated topology 900, a two-dimensional matrix 908 is provided with dimensions represented by X and Y coordinates. Each of the first set of switches 906 selects the first terminal of each cell in the column of cells to the wireless transmitter and/or receiver circuit 902 that supplies current to actuate the coil during wireless charging. are configured to be physically coupled. Each of the second set of switches 904 is configured to selectively couple the second terminal of each cell in the row of cells to the radio transmitter and/or receiver circuitry 902 . A cell is active when both of its terminals are coupled to radio transmitter and/or receiver circuitry 902 .

The use of matrix 908 can significantly reduce the number of switching components required to operate a network of tuned LC circuits. For example, N individually connected cells require at least N switches, whereas a two-dimensional matrix 908 with N cells can be operated with √N switches. The use of matrix 908 can significantly reduce cost and reduce circuit and/or layout complexity. In one example, the 9-cell aspect can be implemented in a 3×3 matrix 908 using 6 switches, saving 3 switches. In another example, the 16-cell aspect can be implemented in a 4x4 matrix 908 using 8 switches, saving 8 switches.

During operation, at least two switches are closed to actively couple one coil to the radio transmitter and/or receiver circuit 902 . Multiple switches can be closed simultaneously to facilitate connecting multiple coils to the wireless transmitter and/or receiver circuit 902 . For example, multiple switches can be closed to enable a mode of operation that drives multiple transmit coils in transmitting power to a receiving device.

FIG. 10 illustrates a second topology 1000 in which each coil or charge cell is individually and/or directly driven by a driver circuit 1002 in accordance with certain aspects disclosed herein. The driver circuit 1002 can be configured to select one or more coils or charging cells 100 from the group of coils 1004 to charge the receiving device. It will be appreciated that the concepts disclosed herein with respect to charge cell 100 may be applied to selective actuation of individual coils or stacks of coils. A charge cell 100 that is not in use receives no current. A relatively large number of charge cells 100 may be in use, and a switching matrix may be employed to drive individual coils or groups of coils. In one example, a first switching matrix can make up the connections that define groups of charge cells or coils used during a charging event, and a second switching matrix (see, for example, FIG. 9) can make up the charging It can be used to activate a group of cells and/or selected coils.

Detecting Removal of a Device from a Multi-Coil Wireless Charger As shown in FIG. 11, a multi-coil wireless charging system 1100 provided in accordance with certain aspects of the present disclosure detects removal of a receiving device 1106 while charging is in progress. can be configured to reliably detect Arbitrary and/or unintentional removal of a receiving device can cause damage to other receiving devices 1108 in addition to potential loss of detection efficiency for nearby devices 1108 . Multi-coil wireless charging system 1100 provides a charging surface 1102 that includes multiple transmission coils 1104 ₁ -1104 _n . In the illustrated example, the receiving device 1106 is removed while receiving charging flux from the nth transmit coil (transmit coil 1104 _n ).

In some cases, the charging surface 1102 continues to provide charging current to the transmission coils _1104n after the receiving device 1106 is removed. An approaching device 1108 may be placed on the charging surface 1102 while the charging current is flowing. The charging current is typically set based on the capabilities of the receiving device 1106 , which may differ from the capabilities of the proximate device 1108 . If the approaching device 1108 is not designed to handle the level of induced current intended for the original receiving device 1106, damage to the approaching device 1108 may occur.

Certain aspects of the present disclosure enable multi-coil wireless charging system 1100 to quickly and reliably detect removal of receiving device 1106 from charging surface 1102 . When the multi-coil wireless charging system 1100 detects the removal of the receiving device 1106, the multi-coil wireless charging system 1100 can cease flowing charging current to the active transmitting coils _1104n . Multi-coil wireless charging system 1100 can configure charging surface 1102 to detect objects, including approaching device 1108, upon detecting removal of receiving device 1106 and cessation of charging current.

According to certain aspects of the present disclosure, removal of the receiving device 1106 can be detected by monitoring one or more specific characteristics of the charging circuit or transmission coils 1104 ₁ -1104 _n . In a particular example, removal of the receiving device 1106 can be detected based on a change in the measured electrical quantity, which can be due to a change in electromagnetic coupling between the transmitting coil 1104 _n and a receiving coil within the receiving device 1106. can.

ここで、Ｌ_Ｔｘは送信機コイルの自己インダクタンスを表し、ｋは結合係数を表している。結合が減少すると結合係数が低くなり、漏れインダクタンスが増加するため、送信機の漏れインダクタンスにより多くの無効エネルギーが蓄積される。漏れインダクタンスに蓄積されたエネルギーは電力伝送に寄与することはなく、漏れインダクタンスにエネルギーが蓄積されると、ＬＣノードにおける電圧が上昇する。 In one example, Dynamic Inference Bond Evaluation (DICE) can be used to detect bond quality in real time. DICE can include an evaluation of the ratio of real power to reactive power in a circuit containing a transmission coil and a series resonant capacitor. The amount of reactive power stored in a transmitter's inductor-capacitor (LC) circuit is greatly affected by the coupling coefficient. The coupling coefficient defines the ratio of mutual inductance to leakage inductance in the LC circuit of a radio transmitter. For example, the leakage inductance in the LC circuit of a radio transmitter can be expressed as:

where L _Tx represents the self-inductance of the transmitter coil and k represents the coupling coefficient. Since less coupling results in a lower coupling coefficient and higher leakage inductance, more reactive energy is stored in the leakage inductance of the transmitter. The energy stored in the leakage inductance does not contribute to power transfer, and the energy stored in the leakage inductance causes the voltage at the LC node to rise.

A particular aspect of the coupling between one or more of the transmit coils 1104 ₁ -1104 _n and the receive device 1106 can be characterized by the voltage measured at the LC node. A measurement of the voltage measured at the LC node may be available for other reasons. In some cases, the voltage at the LC node is monitored as an overvoltage indicator used to protect power electronics and resonant capacitors. In one example, the measurement circuit includes a voltage comparator configured to detect voltages above a threshold level. According to certain aspects disclosed herein, measurement circuitry can be added or existing measurement circuitry can be used to quantify or compare the voltage at the LC node, which varies directly with the quality of the coupling. .

Detecting Removal of a Device from a Multi-Coil Wireless Charger As shown in FIG. 11, a multi-coil wireless charging system 1100 provided in accordance with certain aspects of the present disclosure detects removal of a receiving device 1106 while charging is in progress. can be configured to reliably detect Arbitrary and/or unintentional removal of a receiving device can cause damage to other receiving devices 1108 in addition to potential loss of detection efficiency for nearby devices 1108 . Multi-coil wireless charging system 1100 provides a charging surface 1102 that includes multiple transmission coils 1104 ₁ -1104 _n . In the illustrated example, the receiving device 1106 is removed while receiving charging flux from the nth transmit coil (transmit coil 1104 _n ).

In some cases, the charging surface 1102 continues to provide charging current to the transmission coils _1104n after the receiving device 1106 is removed. An approaching device 1108 may be placed on the charging surface 1102 while the charging current is flowing. The charging current is typically set based on the capabilities of the receiving device 1106 , which may differ from the capabilities of the proximate device 1108 . If the approaching device 1108 is not designed to handle the level of induced current intended for the original receiving device 1106, damage to the approaching device 1108 may occur.

Certain aspects of the present disclosure enable multi-coil wireless charging system 1100 to quickly and reliably detect removal of receiving device 1106 from charging surface 1102 . When the multi-coil wireless charging system 1100 detects the removal of the receiving device 1106, the multi-coil wireless charging system 1100 can cease flowing charging current to the active transmitting coils _1104n . Multi-coil wireless charging system 1100 can configure charging surface 1102 to detect objects, including approaching device 1108, upon detecting removal of receiving device 1106 and cessation of charging current.

According to certain aspects of the present disclosure, removal of the receiving device 1106 can be detected by monitoring one or more specific characteristics of the charging circuit or transmission coils 1104 ₁ -1104 _n . In a particular example, removal of the receiving device 1106 can be detected based on a change in the measured electrical quantity, which can be due to a change in electromagnetic coupling between the transmitting coil 1104 _n and a receiving coil within the receiving device 1106. can.

Passive and Active Ping
FIG. 12 is a flowchart 1200 illustrating a method involving passive ping implemented in a wireless charging device adapted according to certain aspects disclosed herein. At block 1202, the controller may generate a short excitation pulse and may provide the short excitation pulse to a network including a resonant circuit. The network has a nominal resonant frequency, and the short excitation pulse can have a duration of less than half the period of the network's nominal resonant frequency. In another example, the short excitation pulse can have a duration corresponding to multiple periods of the resonant frequency of the network. The nominal resonant frequency can be observed when the transmitting coil of the resonant circuit is isolated from external objects including ferrous, non-ferrous and/or receiving coils of the device being charged.

At block 1204, the controller may measure the resonant frequency of the network or monitor the decay of the network's resonance in response to the pulse. According to certain aspects disclosed herein, the resonant frequency and/or Q factor associated with the network may be altered when a device or other object is placed in close proximity to the transmission coil. The resonant frequency can increase or decrease from the nominal resonant frequency observed when the transmission coil of the resonant circuit is isolated from external objects. Also, the Q-factor of the network can increase or decrease relative to the nominal Q-factor that can be measured when the transmission coil of the resonant circuit is isolated from external objects. According to certain aspects disclosed herein, if the difference in Q factor lengthens or accelerates the decay of the amplitude of oscillations in the resonant circuit relative to the delay associated with the nominal Q factor, the duration of the delay is: It can indicate the presence or type of object placed in close proximity to the transmission coil.

In one example, the controller can measure the resonant frequency of the network using a transition detection circuit configured to detect zero crossings of a signal indicative of the voltage at LC node 510 using a comparator or the like. In some examples, a direct current (DC) component may be filtered from the signal to provide zero crossings. In some examples, a comparator can use an offset to account for the DC component in order to detect common voltage level crossings. A counter can be employed to count the detected zero crossings. In another example, the controller can determine the resonant frequency of the network using a transition detection circuit configured to detect crossings through a threshold voltage by a signal indicative of the voltage at LC node 510, where , the amplitude of the signal is fixed or limited within the range of voltages that can be detected and monitored by logic circuitry. In this example, a counter can be employed to count signal transitions. Network resonant frequencies can also be measured, estimated and/or calculated using other methodologies.

In another example, a timer or counter can be employed to measure the elapsed time for _VLC to decay from the voltage level _V0 to the threshold voltage level. Elapsed time can be used to indicate the decay properties of the network. The threshold voltage level can be chosen to provide sufficient accuracy so that the counter or timer can distinguish between the various responses 800, 820, 840 to the pulse. _VLC can be represented by detected or measured peak, peak-to-peak, envelope and/or rectified voltage levels. Network attenuation properties can also be measured, estimated and/or calculated using other methodologies.

If the controller determines at block 1206 that the change in resonant frequency relative to the nominal resonant frequency indicates the presence of an object in proximity to the transmission coil, the controller may attempt to identify the object at block 1212 . If the controller determines at block 1206 that the resonant frequency is substantially the same as the nominal resonant frequency, then at block 1208 the controller may consider damping characteristics of the amplitude of oscillations in the resonant circuit. The controller shall determine that the resonant frequency of the network is substantially the same as the nominal resonant frequency if the frequencies remain within a specified frequency range centered on or including the nominal resonant frequency. may In some aspects, the controller can use changes in resonant frequencies and damping characteristics to identify objects. In those latter aspects, the controller can continue to block 1208 regardless of the resonant frequency, using changes in the resonant frequency as an additional parameter in identifying objects placed near the transmission coil. can do.

At block 1208, the controller may use a timer and/or count the cycles of oscillation of the resonant circuit that have elapsed between the initial _V0 amplitude and the threshold amplitude used to evaluate the damping characteristics. can. In one example, V ₀ /2 can be selected as the threshold amplitude. _At block 1210, the number of cycles or elapsed time between the initial V0 amplitude and the threshold amplitude is used to characterize the attenuation of the oscillation amplitude in the resonant circuit and compare this characterized attenuation to the corresponding nominal attenuation characteristic. can be done. At block 1210, if no changes in frequency and delay characteristics are detected, the controller may determine that an object is not placed in close proximity to the transmission coil and terminate the procedure. If a change in frequency and/or delay characteristics is detected at block 1210 , the controller can identify the object at block 1212 .

At block 1212, the controller may be configured to identify a receiving device placed on the charging pad that includes the charging surface. The controller should be configured to ignore other types of objects or receiving devices that are not optimally placed on the charging pad (e.g., receiving devices that are out of alignment with the transmission coil that provides the passive ping). can be done. In some aspects, the controller may use a lookup table indexed with an estimate of resonant frequency, decay time, change in resonant frequency, change in decay time, and/or Q factor. The lookup table may provide information identifying a particular device type and/or charging parameters to be used in charging the identified device or type of device.

Passive pings use very short excitation pulses that can be less than half the period of the nominal resonant frequency observed at the LC node 510 of resonant circuit 906 . A conventional ping can actively drive a transmission coil for over 16,000 cycles. The power and time consumed by conventional pings can exceed the power and time usage of passive pings by orders of magnitude. In one example, a passive ping consumes about 0.25 μJ per ping, with a maximum ping time of about 100 μs, whereas a conventional active ping consumes about 80 mJ per ping, with a maximum ping of The time is approximately 90ms. In this example, energy dissipation can be reduced by a factor of 320,000 and the duration of a single ping can be reduced by a factor of 900. In another example, the excitation pulse can have a duration corresponding to multiple cycles (but less than 30 cycles) of the nominal resonant frequency observed at LC node 510 of resonant circuit 906 . In one example, the multi-cycle excitation pulse has a duration that is less than 10 cycles.

The passive ping procedure can also be combined with another low power sensing methodology such as capacitive sensing. Capacitive sensing and the like can provide an ultra-low power detection method for determining the presence or absence of an object in proximity to the charging surface. After capacitive sensing, passive pings can be sent on each coil sequentially or simultaneously to create a more accurate map of where potential receiving devices and/or objects are located. After the passive ping procedure has been performed, an active ping (eg, active digital ping) can be provided to the most likely location of the device. An example algorithm for device location, identification and charging is shown in FIG.

FIG. 13 is a flowchart 1300 illustrating power transfer management procedures that include multiple sensing and/or interrogation techniques that may be employed by wireless charging devices implemented in accordance with certain aspects disclosed herein. This procedure may be initiated periodically, and in some examples after the wireless charging device exits a low power state or sleep state. In one example, this procedure can be repeated at a frequency calculated to provide a sub-second response to placement of the device on the charging pad. The procedure can be re-entered if an error condition is detected during the initial execution of the procedure and/or after charging of the device placed on the charging pad is complete.

At block 1302, the controller may perform an initial search using capacitive proximity sensing. Capacitive proximity sensing can be performed quickly and with low power consumption. In one example, capacitive proximity sensing can be performed iteratively, testing one or more transmit coils in each iteration. The number of transmit coils tested in each iteration can be determined by the number of sensing circuits available to the controller. At block 1304, the controller may determine whether the capacitive proximity sensing has detected the presence or potential presence of an object in proximity to one of the transmission coils. If no object is detected by capacitive proximity sensing, the controller may put the charging device into a low power, idle and/or sleep state at block 1324 . If an object is detected, the controller can initiate passive ping detection at block 1306 .

At block 1306, the controller detects an object in the vicinity of one or more N transmission coils (if capacitive sensing is not used) or detects its presence (if capacitive sensing is not used). Passive ping detection can be initiated to verify and/or assess the properties of objects located in close proximity. Passive ping sensing consumes as much power as capacitive proximity sensing, but can last longer. As an example, each passive ping can be completed in approximately 100 μs and consume 0.25 μJ. A passive ping may be provided to each transmit coil identified as being of interest by capacitive proximity sensing. In some aspects, passive pings may be provided to transmission coils in the vicinity of each transmission coil identified as being of interest by capacitive proximity sensing, including overlaid transmission coils. At block 1308, the controller may determine whether passive ping detection has detected the presence of a potential rechargeable device in proximity to one of the transmission coils, which may be a receiving device. If no potential rechargeable device has been detected, passive ping sensing can continue at block 1306 to test the next coil of the N coils. Passive ping detection continues until all N coils have been tested, as indicated by decision block 1308 . In one example, the controller terminates passive ping detection after all transmit coils have been tested. After all N coils (or in another example a determined subset of the N coils) have been tested, as indicated by decision block 1310, the controller detects an object, as indicated by block 1312. Active digital ping detection can be initiated for all coils that In other aspects, passive ping detection can be resumed after active ping results are obtained.

At block 1312, the controller may query potential rechargeable devices using active pings. Active pings can be provided to transmit coils identified by passive ping detection. In one example, a standard defined active ping exchange can be completed in about 90ms and consumes 80mJ. An active ping can be provided for each transmission coil associated with a potential rechargeable device.

At block 1312, the controller may also identify and configure the rechargeable device. The active ping provided at block 1312 may be configured to prompt the rechargeable device to send a response containing information identifying the rechargeable device. In some examples, the controller may fail to identify or configure potential rechargeable devices detected by passive pings, and the controller may resume passive ping-based searching at block 1306. . At block 1314, the controller may determine whether to use the baseline charging profile or the negotiated charging profile to charge the identified rechargeable device. A baseline or default charging profile may be defined by a standard. In one example, a baseline profile limits charging power to 5W. In another example, the negotiated charging profile allows charging to proceed at up to 15W. Once the baseline charging profile is selected, the controller may initiate power transfer (charging) at block 1320 .

At block 1316, the controller may initiate a standards defined negotiation and calibration process that may optimize power transfer. The controller can negotiate with the rechargeable device to determine an extended power profile that differs from the power profile specified for the baseline charging profile. The controller may determine that the negotiation and calibration process failed and terminate the power transfer management procedure at block 1318 . If the controller determines at block 1318 that the negotiation and calibration process was successful, at block 1320 charging according to the negotiation profile may begin.

At block 1322, the controller may determine whether charging was successfully completed. In some examples, an error may be detected when the negotiated profile is used to control power transfer. In the latter case, the controller may attempt to renegotiate and/or reconfigure the profile at block 1316 . The controller can terminate the power transfer management procedure when charging is successfully completed.

Digital Ping Lockout If any part of the receiving device (e.g., the frame part of the device that is not in close proximity to the device's charging coil) or other object that is not the receiver overlaps the charging surface of the multi-coil pad, such part or Objects can cause recurring digital or active pings after detection of device parts or other objects that are not receivers. Since those parts or objects do not receive, they do not provide ping responses to active or digital pings. Those digital pings can also generate extra signal noise and waste power. Also, if repeating digital pings are frequent enough, they can contribute to unwanted and even harmful heating of objects. Thus, the present disclosure provides a digital ping lockout process that monitors multiple pings for consecutive occurrences and detects a ping after a preset time or count of pings. If no ping response is received from the receiver or object (e.g. negative acknowledgment (NACK)), stop the digital ping (i.e. lock out the digital ping to the object) to reduce signal noise, wasted power, and avoid unnecessary heating of objects.

FIG. 14 illustrates an exemplary scenario in which unwanted digital pings may occur in wireless charging device 1400. FIG. As shown, wireless charging device 1400 includes a charging surface 1402 that includes multiple charging coils (or charging cells) 1404 . In this example, there are 18 coils 1404 labeled LP1-LP18.

Also shown is a receiving (Rx) device 1406, such as an electronic device capable of wireless charging. However, in other examples, device 1406 may be a completely non-receiving device that is detectable with passive or analog pings but is unable to provide ping responses or acknowledgments (ACKs). Additionally, if the Rx device 1406 is a device capable of wireless charging, the coil 1408 within the device 1406 is coupled to one of the coils LP4 (also shown as 1404 ₄ ) used to supply charging energy to the device 1406. May be placed in close proximity. Additionally, a range or region 1410 is shown to indicate the area in which coil 1408 can receive and respond to digital or active pings from coil ₁₄₀₄₄ . Outside this region 1410, the other coils of charging device 1400 are covered by a portion of receiving device 1406 that is detected by passive or analog pings from coil 1404, but not to those portions of device 1406. does not receive a ping response because it has no coils or other sensing/transmitting means. Examples of charging coils of the charging device 1400 that can detect the device 1406 by passive or analog ping, but do not receive a ping response, include coils LP1, LP2, LP5, LP7 shown in horizontal hatching. ˜LP10 (ie, 1404 ₁ , 1404 ₂ , 1404 ₅ , 1404 ₇ to 1404 ₁₀ ). For those coils 1404 ₁ , 1404 ₂ , 1404 ₅ , 1404 ₇ to 1404 ₁₀ , the passive ping detects the presence of those parts or objects, so then the normal procedure is to A digital or active ping is issued using those coils, such as. However, as mentioned above, active or digital pings with those coils can cause increased system noise, wasted power, and unwanted heating of objects.

FIG. 15 can be implemented in a wireless charging device such as device 1400 that stops digital pings (i.e., locks out digital pings) by coils that do not or will not receive a ping response from a receiving device or object. 15 shows a flow diagram of method 1500. FIG. This method 1500 reduces noise, power waste, and heating that can occur with the normal procedure of FIG. Specifically, the method 1500 first includes determining whether an object has been detected by analog pings from at least one coil (eg, 1404 ₁ ), as indicated at block 1502 . If an object is detected, flow proceeds to block 1504 and a digital ping is performed by that coil. If no object is detected, flow proceeds to block 1506 where a negative acknowledgment (NACK) counter or similar function is reset. Note that the NACK counter is used to count each instance when the coil does not receive a digital ping response in order to limit the number of digital pings sent by the coil, as described below. . Note that flow returns from block 1506 to the start of method 1500 where the passive or analog ping process is resumed and an attempt is made to detect whether an object is present.

After the digital ping is performed at block 1504 , a check is made whether a ping response to the digital ping was received at the coil from the object, as indicated at decision block 1508 . If an acknowledgment was received, flow proceeds to block 1510 where a negative acknowledgment (NACK) count or counter is reset.

Alternatively, if at block 1510 no response is received to the digital ping, flow proceeds to block 1512 where a NACK count or counter is incremented by one. Flow then proceeds to decision block 1514 where the current value of the NACK counter is compared to a preset threshold corresponding to the maximum number of consecutive no responses from each digital ping. If the NACK count or the current value of the counter does not exceed the threshold, flow returns to the start to analog ping, determining the presence of an object by the analog ping at block 1502 and the object as determined by the analog ping. is still present, move on to subsequent digital pings.

If the NACK count or counter exceeds a preset threshold, as determined at block 1514 (meaning that the maximum number of consecutive unacknowledged digital pings have been sent), flow proceeds to block 1516. proceed to At block 1516, the analog ping can continue to check for the presence of the object. Decision block 1516 (and analog ping) continues to loop until the object moves and is no longer detected. Block 1516 continues to loop so digital ping is stopped or locked out while an unresponsive object is present and detected by the coil. Once the object is removed, flow proceeds to block 1506 where the NACK count or counter is reset before returning to the start of method 1500 . Therefore, the method 1500 limits the number of consecutive digital pings emitted from the coil to unresponsive objects. In some aspects, the NACK count is set to, for example, but not limited to, 3, and may be less or more.

In a further aspect, the method 1500 can be performed for each coil that detects objects with passive pings. For each of the coils, for example, each coil LP1, LP2, LP5, LP7-LP10 (i.e., 1404 ₁ , 1404 ₂ , 1404 ₅ , 1404 ₇ -1404 ₁₀ ) detecting receiving device 1406 of FIG. Method 1500 may be implemented.

FIG. 16 shows an example hardware implementation of an apparatus 1600 that can be incorporated into a charging device that enables wireless charging of batteries. In some examples, device 1600 can perform one or more functions disclosed herein. According to various aspects of the present disclosure, any element, any portion of an element, or any combination of elements disclosed herein may be implemented using processing circuitry 1602 . Processing circuitry 1602 may include one or more processors 1604 controlled by some combination of hardware and software modules. Examples of processor 1604 include microprocessors, microcontrollers, digital signal processors (DSPs), SoCs, ASICs, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, sequencers, gate logic, discrete hardware. Circuitry and other suitable hardware configured to perform the various functions described throughout this disclosure are included. One or more processors 1604 may include specialized processors that perform specific functions and may be configured, enhanced, or controlled by one of the software modules 1616 . The one or more processors 1604 may be configured through a combination of software modules 1616 loaded during initialization, and further configured by loading and unloading one or more software modules 1616 during operation. may be configured.

In the depicted example, processing circuitry 1602 may be implemented with a bus architecture generally indicated by bus 1610 . Bus 1610 may include any number of interconnecting buses and bridges, depending on the particular application of processing circuitry 1602 and overall design constraints. Bus 1610 links various circuits, including one or more processors 1604 and storage 1606 . Storage 1606 can include memory devices and mass storage devices and is also referred to herein as computer-readable media and/or processor-readable media. Storage 1606 may include temporary and/or non-transitory storage media.

Bus 1610 may also link various other circuits such as timing sources, timers, peripherals, voltage regulators and power management circuits. Bus interface 1608 may provide an interface between bus 1610 and one or more transceivers 1612 . In one example, a transceiver 1612 can be provided to allow the apparatus 1600 to communicate with charging or receiving devices according to standard defined protocols. Depending on the nature of device 1600, a user interface 1618 (eg, keypad, display, speaker, microphone, joystick) may also be provided and communicatively coupled to bus 1610 either directly or via bus interface 1608. be able to.

Processor 1604 can be responsible for managing bus 1610 and overall processing, including executing software stored in computer-readable media, including storage 1606 . In this regard, processing circuitry 1602, including processor 1604, can be used to implement any of the methods, functions and techniques disclosed herein. Storage 1606 can be used to store data that is manipulated by processor 1604 when executing software, which can be configured to perform any one of the methods disclosed herein. can.

One or more processors 1604 of processing circuitry 1602 may execute software. Software includes instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, whether referred to as software, firmware, middleware, microcode, hardware description languages, etc. , software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, and the like. The software may reside in computer readable form in storage 1606 or may reside on an external computer readable medium. External computer-readable media and/or storage 1606 can include non-transitory computer-readable media. Non-transitory computer readable media include, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs)), smart cards, flash memory Devices (e.g., "flash drives", cards, sticks, key drives), RAM, ROM, programmable read-only memory (PROM), erasable PROM (EPROM) including EEPROM, registers, removable disks, and Any other suitable medium for storing readable software and/or instructions may be included. Computer readable media and/or storage 1606 can also include, for example, carrier waves, transmission lines, and any other suitable medium for transmitting software and/or instructions that can be accessed and read by a computer. can. Computer readable media and/or storage 1606, whether resident in processing circuitry 1602, processor 1604, or external to processing circuitry 1602, may be distributed among multiple entities including processing circuitry 1602. may be Computer readable media and/or storage 1606 may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure, depending on the particular application and overall design constraints imposed on the overall system. .

Storage 1606 may maintain and/or organize software, modules, applications, programs, etc. in loadable code segments, also referred to herein as software modules 1616 . Each of the software modules 1616 is installed or loaded on the processing circuitry 1602 and, when executed by the one or more processors 1604 , provides instructions and data that contribute to the runtime image 1614 that controls the operation of the one or more processors 1604 . can contain. The specific instructions, when executed, may cause processing circuitry 1602 to perform functions in accordance with certain methods, algorithms and processes described herein.

Some of the software modules 1616 may be loaded during initialization of the processing circuitry 1602, and those software modules 1616 are configured to enable the various functions disclosed herein to be performed. Processing circuitry 1602 may be configured. For example, a number of software modules 1616 may configure internal devices and/or logic circuitry 1622 of processor 1604, to external devices such as transceiver 1612, bus interface 1608, user interface 1618, timers, math coprocessors, and the like. can manage access to Software module 1616 may include a control program and/or operating system that interacts with interrupt handlers and device drivers and controls access to various resources provided by processing circuitry 1602 . Resources can include memory, processing time, access to transceiver 1612, user interface 1618, and the like.

One or more processors 1604 of processing circuitry 1602 are multifunctional, whereby several of the software modules 1616 are loaded and configured to perform different functions or different instances of the same function. Additionally, the one or more processors 1604 may be adapted to manage background tasks initiated in response to input from the user interface 1618, transceiver 1612 and device drivers, for example. To support the performance of multiple functions, one or more processors 1604 may be configured to provide a multitasking environment whereby each of the multiple functions can Implemented as a set of tasks provided by one or more processors 1604 . In one example, a multitasking environment may be implemented using a time-sharing program 1620 that passes control of the processor 1604 between different tasks such that each task is responsible for completing outstanding operations. Control of the one or more processors 1604 is returned to the timesharing program 1620 at times and/or in response to inputs such as interrupts. When a task has control of one or more processors 1604, the processing circuitry is effectively specialized for the purposes addressed by the functions associated with the control task. Time-sharing programs 1620 may include an operating system, a main loop that transfers control on a round-robin basis, functions that assign control of one or more processors 1604 according to function priority, and/or control of one or more processors 1604. may include an interrupt-triggered main loop that responds to external events by providing .

In one aspect, apparatus 1600 includes a wireless charging device having a battery charging power supply coupled to a charging circuit, a plurality of charging cells, and a controller included in or implemented by one or more processors 1604. or can operate as a wireless charging device. A plurality of charge cells can be configured to provide a charge surface. The at least one coil can be configured to direct the electromagnetic field through the charge transfer region of each charge cell. The controller causes the charging circuit to supply charging current to the resonant circuit when the receiving device is placed on the charging surface, the change or rate of change in voltage or current level associated with the resonant circuit, or transmitted to the receiving device. A change or rate of change in power is detected and the receiving device is removed from the charging surface when the change or rate of change in voltage or current level or the change or rate of change in power transmitted to the receiving device exceeds a threshold. can be configured to determine that

In some implementations, the resonant circuit includes a transmission coil. The controller can be further configured to determine that the receiving device has been removed from the charging surface when the voltage measured at the terminals of the transmission coil exceeds a threshold voltage level. In one example, the threshold voltage level is maintained by a lookup table and determined when the transmission coil is electromagnetically decoupled. In another example, the threshold voltage level is determined when the receiving device is first placed on the charging surface.

In certain implementations, the controller further causes the transmission coil to transmit a ping that can be received by a power receiving device (e.g., PRx) in the vicinity of the wireless charging device (e.g., located on the wireless charging surface). It is configured. Additionally, the transmit coil can be configured to receive a ping response, such as an ASK modulated response from a power receiving device (PRx). Additionally, the magnitude measured in the resonant circuit will be less than the threshold current level. In one example, the threshold current level is maintained by a lookup table and determined when the object is not electromagnetically coupled with the coil of the resonant circuit. In another example, the threshold current level is determined when the receiving device is first placed on the charging surface.

In some implementations, apparatus 1600 has one or more sensors positioned proximate to the outer surface of the charging device. The controller may be further configured to receive measurements from the one or more sensors and measure a voltage or current level associated with the resonant circuit when one of the measurements indicates physical removal of the receiving device. can.

In some implementations, the storage 1606 holds instructions and information that are sent to the one or more processors 1604 by at least one passive ping to the surface of the charging device using at least one coil of the charging device. It is configured to detect nearby objects. Specifically, this ability to detect objects with passive or analog pings can include, for example, the process of block 1502 of FIG.

In a further embodiment, storage 1606 retains instructions and information configured to cause one or more processors 1604 to ping detected objects with one or more active pings from at least one coil. It is Specifically, this capability of digital or active ping can include, for example, the process of block 1504 of FIG.

Additionally, the storage 1606 retains instructions and information, the instructions directing the one or more processors 1604 to generate at least one ping response from an object in response to one or more active pings from at least one coil. It is configured to determine whether or not the signal has been received by the coil. Specifically, this function can include, for example, the process of block 1506 of FIG.

Further, the storage 1606 retains instructions and information, the instructions instructing the at least one coil to receive a ping response after a count of consecutively emitted active pings from the at least one coil exceeds a preset number. If not received, the one or more processors 1604 are configured to stop pinging the detected object with active pings from the at least one coil. Specifically, this functionality may include, for example, the processes of blocks 1512 and 1514 of FIG.

FIG. 17 is a flowchart illustrating a method 1700 for operating a charging device according to certain aspects of this disclosure. This method 1700 may be performed by a controller within the charging device. At block 1702, the controller can detect an object proximate to the surface of the charging device by at least one passive ping using at least one coil of the charging device.

Additionally, the controller can ping the detected object with one or more active pings from at least one coil, as shown in block 1704 . Further, the controller can determine whether a ping response is received on the at least one coil from the object in response to one or more active pings from the at least one coil, as shown in block 1706. . In addition, the controller may determine if no ping response is received on at least one coil after the count of consecutive active pings emitted from at least one coil exceeds a preset number, as indicated in block 1708 . , with active pings from at least one coil, can stop pinging the detected object.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. For this reason, the claims are not intended to be limited to the aspects shown herein, but are to be accorded full scope consistent with the language of the claims, revising to elements in the singular. References shall mean "one or more" rather than "only" unless otherwise specified. Unless otherwise specified, the term "some" refers to one or more. All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later become known to those of skill in the art are expressly incorporated herein by reference. and is intended to be included in the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public, whether or not such disclosure is explicitly recited in the claims. Unless a claim element is explicitly recited using the language "means for," and in the case of a method claim, a "step for No claim element should be construed under the provisions of 35 U.S.C.

Claims (15)

A method of operating a charging device, comprising:
detecting an object proximate to the surface of the charging device by at least one passive ping using at least one coil of the charging device;
pinging the detected object with one or more active pings from the at least one coil;
determining whether a ping response is received at the at least one coil from an object in response to one or more active pings from the at least one coil;
an active ping from the at least one coil when no ping response is received on the at least one coil after a count of consecutive active pings emitted from the at least one coil exceeds a preset number; and c. stopping pinging the detected object using the . The method of claim 1, wherein
periodically detecting whether an object is in proximity to the surface of the charging device with a passive ping after stopping pinging the detected object using an active ping;
resetting a count of consecutive active pings when an object is no longer detected by periodically detecting whether an object is in proximity to the surface of the charging device with a passive ping; A method, further comprising: The method of claim 1, wherein
The method further comprising resetting a count of successively issued active pings proximate a surface of the charging device by at least one passive ping using at least one coil of the charging device. The method of claim 1, wherein
The method further comprising resetting a count of continuously issued active pings when an object is not detected in response to one or more passive pings from the at least one coil. The method of claim 1, wherein
The object includes a receiving device comprising at least one receiving coil portion operable to respond to active pings and at least one portion detectable by passive pings but not responding to active pings. A method characterized by: a charging device,
a charging circuit;
a controller, the controller comprising:
detecting an object proximate to the surface of the charging device by at least one passive ping using at least one coil of the charging device;
pinging a detected object with one or more active pings from the at least one coil;
determining whether a ping response is received at the at least one coil from an object in response to one or more active pings from the at least one coil;
an active ping from the at least one coil when no ping response is received on the at least one coil after a count of consecutive active pings emitted from the at least one coil exceeds a preset number; A charging device configured to stop pinging an object detected using a . The charging device according to claim 6, wherein
The controller further
periodically detecting whether an object is in proximity to the surface of the charging device with a passive ping after stopping pinging the detected object using an active ping;
configured to reset a count of consecutively issued active pings when an object is no longer detected by periodically detecting whether an object is in proximity to the surface of the charging device with a passive ping; A charging device, characterized in that: The charging device according to claim 6, wherein
The controller further
At least one passive ping using at least one coil of the charging device is configured to reset a count of successive active pings proximate a surface of the charging device. charging device. The charging device according to claim 6, wherein
The controller further
A charging device configured to reset a count of continuously issued active pings when an object is not detected in response to one or more passive pings from the at least one coil. The charging device according to claim 6, wherein
The object includes a receiving device comprising at least one receiving coil portion operable to respond to active pings and at least one portion detectable by passive pings but not responding to active pings. A charging device characterized by: A processor-readable storage medium,
When executed by a processor, one or more processors:
detecting an object proximate to the surface of the charging device by at least one passive ping using at least one coil of the charging device;
pinging the detected object with one or more active pings from the at least one coil;
determining whether a ping response is received at the at least one coil from an object in response to one or more active pings from the at least one coil;
an active ping from the at least one coil when no ping response is received on the at least one coil after a count of consecutive active pings emitted from the at least one coil exceeds a preset number; and stopping pinging objects detected using 12. The processor-readable storage medium of claim 11, comprising:
periodically detecting whether an object is in proximity to the surface of the charging device with a passive ping after stopping pinging the detected object using an active ping;
resetting a count of consecutive active pings when an object is no longer detected by periodically detecting whether an object is in proximity to the surface of the charging device with a passive ping; A processor-readable storage medium further comprising code for causing the one or more processors to execute. 12. The processor-readable storage medium of claim 11, comprising:
causing the one or more processors to reset a count of successive active pings proximate the surface of the charging device by at least one passive ping using at least one coil of the charging device; A processor-readable storage medium further comprising code. 12. The processor-readable storage medium of claim 11, comprising:
further code that causes the one or more processors to reset a count of consecutive active pings when an object is not detected in response to one or more passive pings from the at least one coil; A processor-readable storage medium comprising: 12. The processor-readable storage medium of claim 11, comprising:
The object includes a receiving device comprising at least one receiving coil portion operable to respond to active pings and at least one portion detectable by passive pings but not responding to active pings. A processor-readable storage medium characterized by:

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